We have done emergency vascularized composite graft by microsurgical technique for severe open fractures. It is essential for open injury to cover bones, joints, tendons etc. Vascularized composite graft for open fracture with tissue defect covers bone etc., prevents infection and promotes subsequent early functional recovery. Eighteen patients aged 3–55year old with an average age of 23.1y.o. were treated with this methos. Traffic injuries of leg and foot in children were the most common and others were open severe fracture with tissue defects. The composite graft employed were peroneal osteocutaneous flap, latissimus dolsi flap, parascapular flap and groin flap. The advantage of these flaps to cover the damaged structure primrily facilitatrs rapid tissue repair without infection and scar formation. In fact, except one reoperation due to a skin necrosis in parascapular flap, all grafted flaps successfully repaired the severe damaged bone and joint. Sufficient perfusion of antibiotics by these vascularized flap prevents infection in all cases. Primary emergency vascularized composite graft for severe open fracture with tissue defect is shown to be extremely useful method with rapid repair and functionnal recovery

Infected non-union after severe open fracture or unsuitable fracture operation is frequently associated with bone defect and its treatment has been controversial. We have used microsurgical vascularised composite graft for these problematic cases. Fifty one patients aged 17∼70 year old (43.6 years old in average), including 41 men and 10 women. Follow-up has been more than 6 months. The vascularised composite graft included a free fibular osteocutaneous flap in 41 cases, a vascular pedicled fibular osteocutaneous flap in 2 cases, a free iliac osteocutaneous flap in 5 cases, a vascularised cutaneous flap in 2 cases and other in one case. All infected non-unions were united without trouble and co-existing infection was successfully eradicated. This method also enables the patients rapid bone union and subsequent early functional recovery. This success was attributed to greater transport of oxygen and good antibiotic perfusion in presence of good blood supply. We conclude that microsurgical vascularised composite graft for infected non-union is an extremely useful method with early bone union and subsidence of infection

Introduction: Screws placed in the fibula do not have a satisfactory purchase during internal fixation of an osteoporotic ankle fracture. Tibia-pro-fibula screws that extend from the fibula into the distal tibial metaphysis provide additional purchase. The purpose of this study is to investigate if purchase of these screws can be enhanced further by injecting calcium sulfate and calcium phosphate composite graft in the drill holes prior to insertion of the screws. Methods: Bone density was quantified using DEXA scan in paired cadaver legs. One leg from each pair was randomly selected for injection of composite graft into screw holes before insertion of the screws. Two screws were inserted through the fibula into the distal tibial metaphysis in each leg, at the level of the syndesmosis under fluoroscopy in a standardized fashion using a jig. The screws were pulled out using a materials testing machine. Stiffness, force, displacement, and energy required were recorded. Results: After testing 4 pairs of cadaver legs, a statistically significant difference was noted in displacement, failure load, and failure energy between augmented and non-augmented screws, with the augmented screws being considerably stronger. Of the two screws the distal, when compared to the proximal one, required more displacement, higher force and energy to fail whether augmented with composite graft or not. Conclusion: Screws augmented with composite graft provide significantly greater purchase in an osteoporotic distal tibial metaphysis than non-augmented screws. Clinical relevance: Use of composite graft to augment purchase of the screws inserted in the distal tibial metaphysis may enhance the stability of the internal fixation of an osteoporotic ankle fracture. This will enable early weight-bearing mobilization and return to function which is important in elderly patients

Introduction: Bone marrow derived stromal stem cells (BMSSC’s) have the ability to differentiate into a variety of mesenchymal tissues including bone. The objective of this study was to evaluate the use a hydroxyapatite – BMSSC (HA-BMSSC) composite graft for posterior spinal fusion in a rabbit model. Method: The HA- BMSSC composite graft was prepared by seeding rabbit marrow derived BMSSC’s onto 5 grams of HA granules which were cultured for a further 7 days prior to implantation. Bilateral posterior L4–L5 interlamina spinal fusion was performed using the HA- BMSSC composite graft (4 Rabbits), hydroxyapatite(HA) granules (6 rabbits) or autologous bone graft obtained from the iliac crest (6 rabbits). Rabbits were sacrificed at 5 weeks. Fusion was assessed by manual palpation. Quantitative histological analysis of cartilage, fibrous tissue and bone in the mid portion of the graft was performed using image analysis software. Results: Three of four of the HA- BMSSC grafts fused successfully compared to 5 of 6 of the autologous bone grafts and 0 of 6 of the HA control grafts. The fusion rate was significantly higher in the iliac crest and HA- BMSSC groups than the HA control group (p< 0.05). In both the HA control and HA stem cell composite grafts there was ingrowth of new bone and encasement of HA granules by new trabecular bone at the graft – host interface. Within the mid region of the grafts there was bone formation in 2 of four fusion masses in the HA- BMSSC group comprising 26% and 45% of tissue in the area examined. In contrast bone formation was seen in the centre of only one of the six 6 HA fusion masses and amounted to only 2% of tissue. There was no significant difference in average percentage area of new bone, cartilage or fibrous tissue within the central region of the HA and HA-BMSSC grafts. There was a higher mean percentage area of new bone formation within the autologous bone graft (27%) than the HA control group (0.3%). p< 0.02. Discussion: The BMSSC –HA composite was as effective as autologous graft and superior to HA in promoting fusion, but HA when used alone was ineffective. A positive finding to support the osteogenic potential of the stem cell loaded HA granules was the presence of moderate amounts of enchondral new bone isolated within the central regions of the graft away from the graft host interface in 2 of 4 fusion masses. In contrast the HA control grafts only supported significant amounts of bone formation in the periphery, adjacent to the host bed

Purpose: The current gold standard for spinal arthrodesis, autologous bone graft harvested from the iliac crest, has several disadvantages including donor site morbidity, blood loss, delayed wound healing, and increased operative time. Our study explores a Demineralized Bone Matrix-Calcium Sulfate(DBM-CaSO4) composite graft with autologous bone marrow aspirate (BMA), and compares it to autologous iliac crest bone graft in lumbar and lumbosacral spinal fusions. Method: A total of 80 patients were recruited for the study and randomised, via a computer-generated ran-domisation schedule, to autologous iliac crest bone graft (control) or DBM-CaSO4 composite graft with BMA (study) groups. Patients were evaluated at three-months, six-months, 12-months and 24-months post-operatively with questionnaires to evaluate clinical outcome (Oswestry disability questionnaire (ODI), visual analogue pain scales (VAS), and validated SF-36) and with posteroanterior and lateral x-rays of the spine to evaluate radiological outcome. Results: At 24-months post-operatively, there were no statistical differences seen between the two groups based on the clinical outcomes measured. Average ODI values were 27.19 for the control group versus 22.68 for the study group (p > 0.05). The average back VAS pain for the control group was 3.50 versus 3.51 for the study group (p > 0.05). The SF-36 score was 89.22 for the control group versus 91.56 for the study group (p > 0.05). The average operative time was 115.7 minutes for the control group versus 104.2 minutes for the study group (p: 0.014). Average calculated blood loss was 571.9 cc for the control group versus 438.2 cc for the study group (p: 0.025). The Lenke score was 1.92 for the control group versus 2.66 for the study group (p: 0.004). Conclusion: At two year follow-up, radiographic fusion was slightly higher in the ICBG. However, clinical outcomes were equivalent in both groups. Moreover, the DBM-CaSO4 and BMA composite graft offered the advantages of decreased blood loss and shorter operative time. Therefore, the DBM-CaSO4 and BMA composite graft represents a viable alternative to autologous iliac crest bone graft in carefully selected patients undergoing spinal arthrodesis

Purpose: Bone grafting of subchondral voids during ORIF of tibial plateau fractures is commonly performed. The efficacy of various graft materials to resist post-operative articular displacement and stimulate bone regeneration in the grafted zone, remains largely unstudied. Studies in animals with a new composite material have shown that this composite material leads to greater bone formation and stronger bone versus autograft at 13 and 26 weeks. This study was designed to determine whether this material helps resist articular fragment displacement and leads to stronger bone regeneration and better functional outcome in the treatment of tibial plateau fractures. Methods: Thirty four patients with unilateral tibial plateau fractures (OTA 41A-B), were enrolled in a prospective multicenter single cohort study. The treatment protocol included ORIF and defect augmentation with a composite bone graft substitute (PRODENSE®, Wright Medical Technology). Reduction and bone formation was evaluated and followed with both plain radiographs and CT scans obtained immediately postop and at 12 and 24 weeks. Functional outcome was assessed using the SMFA scores. CT analysis was performed by an independent musculoskeletal radiologist who quantified maintenance of reduction of the articular surface and bone density within the grafted area. Results: Eighteen of the 34 enrolled patients were eligible for follow-up at 24 weeks (sixteen were not yet eligible for the 24 week time point). Mean change in articular reduction was 0.75mm, Density measures in the region of the initial subchondral void decreased from a mean of 1400 Hounsfield units at baseline (immediately post-op) to 600 at 24 weeks, suggesting bone regeneration and normal remodeling. Short form Musculoskeletal Function Assessment activity scores improved from 55.15 (SD=42.8) at baseline to 20.92 (SD=18.09) at 24 weeks. Complications include 1 DVT, 3 infections and 1 cellulitis, all of which resolved. There was an additional infection that required revision of the ORIF. Conclusions and Significance: Serial CT evaluations revealed maintenance of post-operative reduction with displacement of less than 1mm. Bone density, in the region of the grafted area was near normal and confirms that the composite graft material promotes strong bone regeneration. Functional outcomes improved with time from surgery and approached that of uninjured cohorts

Aims

Impaction bone grafting with milled human allograft is the gold standard for replacing lost bone stock during revision hip surgery. Problems surrounding the use of allograft include cost, availability, disease transmission and stem subsidence (usually due to shear failure of the surrounding allograft).

The aim of this study was to investigate various polymers for use as substitute allograft. The ideal graft would be a composite with similar mechanical characteristics as allograft, and with the ability to form de novo bone.

Impaction bone grafting with milled human allograft is the gold standard for replacing lost bone stock during revision hip surgery. Problems surrounding the use of allograft include cost, availability, disease transmission and stem subsidence (usually due to shear failure of the surrounding allograft).

The aim of this study was to investigate various polymers for use as substitute allograft. The ideal graft would be a composite with similar mechanical characteristics as allograft, and with the ability to form de novo bone.

High and low molecular weight (MW) forms of three different polymers (polylactic acid (PLA), poly (lactic co-glycolic) acid (PLGA) and polycaprolactone (PCL)) were milled, impacted into discs, and then tested in a custom built shear testing rig, and compared to allograft.

A second stage of the experiment involved the addition of skeletal stem cells (SSC) to each of the milled polymers, impaction, 8 days incubation, and then tests for cell viability and number, via fluorostaining and biochemical (WST-1) assays.

The shear strengths of both high/ low MW PLA, and high/low MW PLGA were significantly higher than those of milled allograft (P<0.001, P<0.001, P<0.005 and P<0.005) but high and low MW PCL was poor to impact, and had significantly lower shear strengths (P<0.005, P<0.001). Fluorostaining showed good cell survival on high MW PLA, high MW PCL and high MW PLGA. These findings were confirmed with WST-1 assays.

High MW PLA as well as high MW PLGA performed well both in mechanical testing and cell compatibility studies. These two polymers are good contenders to produce a living composite for use as substitute human allograft in impaction bone grafting, and are currently being optimised for this use via the investigation of different production techniques and in-vivo studies.

In 1999, we developed a technique for biological reconstruction after excision of a bone tumour, which involved using autografts of the bone containing the tumour treated with liquid nitrogen. We have previously reported the use of this technique in 28 patients at a mean follow up of 27 months (10 to 54).

In this study, we included 72 patients who underwent reconstruction using this technique. A total of 33 patients died and three were lost to follow-up, at a mean of 23 months (2 to 56) post-operatively, leaving 36 patients available for a assessment at a mean of 101 months 16 to 163) post-operatively. The methods of reconstruction included an osteo-articular graft in 16, an intercalary in 13 and, a composite graft with prosthesis in seven.

Post-operative function was excellent in 26 patients (72.2%), good in seven (19.4%), and fair in three (8.3%) according to the functional evaluation system of Enneking. No recurrent tumour occurred within the grafts. The autografts survived in 29 patients (80.6%), and the rates of survival at five and ten years were 86.1% and 80.6 %, respectively. Seven of 16 osteo-articular grafts (44%) failed because of fracture or infection, but all the composite and intercalary grafts survived.

The long-term outcomes of frozen autografting, particularly using composite and intercalary grafts, are satisfactory and thus represent a good method of treatment for patients with a sarcoma of bone or soft tissue.

Cite this article: Bone Joint J 2014;96-B:555–61.

Purpose: To test a CaSO4/CaPO4-TCP composite bone graft substitute in a crtically sized bone defect. Method: Twenty dogs had a contained medullary defect created in the proximal humerus. In ten dogs, the defect was treated with CaSO4/CaPO4-TCP composite graft (PRO-DENSE. ™. , Wright Medical) and studied for 13 weeks (N=5) and 26 weeks (N=5). In the other ten dogs, the defect was treated with autograft and followed for 13 weeks. An additional ten unoperated humeri were used to establish the properties of normal canine bone. The area fraction, ultimate compressive stress and modulus of elasticity of bone in the experimental and normal humeri were quantified using histomorphometric and mechanical methods and analyzed using the Mann-Whitney test. Results: At 13 weeks, the area fraction, compressive stress and modulus of elasticity of new bone in the defects was several-fold greater (p ≤ 0.005) using CaSO4/CaPO4-TCP composite graft compared to defects treated with autograft. The area fraction and compressive stress of new bone using CaSO4/CaPO4-TCP composite graft were also several fold greater (p≤.009) compared to normal bone, but there was no difference in the modulus of elasticity. Although the compressive stress was still greater (p=0.047) at 26 weeks for defects treated with the composite graft compared to normal bone, the regenerated bone had remodeled to a normal cancellous architecture, incorporating minute fragments of residual graft. Conclusion: CaSO4/CaPO4-TCP composite graft produced a several-fold greater amount and strength of bone than autogenous graft bone at 13 weeks. There was no modulus mismatch between the regenerated and native cancellous bone. The composite graft holds promise for non-load bearing applications where dense, strong bone formation at earlier time points would be advantageous, potentially resulting in quicker return to activity

1. This paper reports a histological study of the fate of sheep and calf cancellous bone grafts impregnated with autologous red marrow of Wistar rats and implanted intramuscularly as composite xenograft-autografts for two to twelve weeks. It also includes some biochemical estimations of certain types of sheep and calf bone used to prepare these composite grafts. 2. Only one of 223 devitalised bone xenografts implanted without autologous marrow formed new bone; in contrast 216 of 223 transplanted with marrow formed new bone. 3. The new bone formed by the composite grafts is derived from the autologous marrow. There was no evidence for an inductive effect upon the marrow of the various types of xenograft bone studied as described previously for allograft bone (Burwell 1966). 4. The highest score of new bone formation was found in composite grafts based on fully deproteinised sheep iliac bone prepared at Oswestry. Statistically this score was significantly higher than those registered by composite grafts prepared from intact (frozen and freeze-dried), decalcified (frozen and freeze-dried) and Kiel sheep bone, and by Kiel and Oswestry calf bone (Table II). 5. The histological evidence reported suggests that the high score with the sheep Oswestry composite grafts is because Oswestry bone is feebly immunogenic, if at all; and that such feeble or absent immunogenicity permits more marrow cells to differentiate into osteoblasts and lay down new bone without impediment. 6. The lower scores of new bone formation in most of the undeproteinised composite grafts of sheep origin–intact frozen, intact freeze-dried and Kiel–are attributed to residual immunogenicity within the organic material of the donor bone, because each type evoked the formation of mature plasma cells. 7. The Kiel bone grafts appeared to evoke less of a plasma cell reaction and may be less immunogenic than the intact and decalcified bone xenografts. 8. The sheep Oswestry CXA's formed significantly more new bone than did the calf Oswestry CXA's. This difference may be due to the different physical properties of the bone obtained from old sheep compared with the bone obtained from a young calf

1. The present study is an attempt to analyse and apportion significance to the role of inductive mechanisms in bone transplantation. 2. The experimental model used in the present work is that of the composite homograftautograft of cancellous bone previously described (Burwell 1964a). 3. Iliac bone was removed from hooded rats and washed free from its marrow. The bone was then treated by various physical and chemical methods (some of which have been used by other workers to prepare bank bone), namely freezing (-20 degrees Centigrade, -79 degrees Centigrade, -196 degrees Centigrade); freeze-drying (without sterilisation, sterilisation with high energy radiation, sterilisation with ß-propiolactone); decalcification (with E.D.T.A.); irradiation (in the frozen state at a dose of 4 million rads); boiling in water; immersion in merthiolate solution; extraction of organic components with ethylenediamine: and calcining at 660 degrees Centigrade. The treated bone was then impregnated with fresh autologous marrow procured from the femoral shaft of the Wistar rat into which the treated composite graft was to be implanted. The grafts were inserted intramuscularly and removed for study after two, six and twelve weeks. 4. After fixation, serial sectioning and staining, each graft was examined microscopically, and the proportion of new bone/grafted bone scored using an arbitrary scale (0-4). The mean score (and the standard error of the mean score) was then plotted for each treated composite graft and also for several types of fresh cancellous bone grafts. 5. It was found (Fig. 2) that the various treated composite grafts formed a spectrum of bone-forming capacities–the maximum scores being attained by the frozen and freeze-dried composite grafts, the lowest scores by the "deproteinised" composite grafts. 6. The reasons for these differences are discussed. It is concluded that cancellous bone, after transplantation, has the property to induce and promote osteogenesis in marrow; moreover, that this property is contained in the organic components of bone. 7. From the standpoint of inductive mechanisms, cancellous bone treated by freezing or freeze-drying seems to be the most suitable devitalised bone for grafting purposes; bone which has been boiled or merthiolated less suitable; and "deproteinised" bone the least suitable. 8. Freeze-dried bone sterilised physically (by high energy radiation) or chemically (by ß-propiolactone) did not form significantly less new bone than did freeze-dried bone which had not been sterilised. 9. Remodelling mechanisms in bone transplantation are briefly discussed and attention drawn to the deficiencies of present knowledge. The quantitative studies of other workers have indicated that freeze-dried bone may be more rapidly remodelled than is frozen bone. 10. The importance of fresh red marrow in promoting osteogenesis in bone transplantation and in the healing of certain fractures, is emphasised. It seems likely that the interrelationship of bone and marrow revealed by experiment has wider significance not only in health and in response to injury but also in causation of certain idiopathic bone disorders

Arthrodesis of the spine is the preferred surgical treatment for a number of pathological disorders. This process is dependent on three primary components: osteogenic cells with osteoblastic potential, osteoinductive growth factors and an osteoconductive scaffold that facilitates bone formation and vascular ingrowth. Several systemic and local factors are known to affect the rate of spinal fusion. Autogenous bone graft remains the gold standard graft material for spinal fusion. It is the only graft material that supplies the three primary components necessary for a solid fusion. Unfortunately autogenous bone is only available in limited quantities and the procurement of autograft is associated with significant donor site morbidity. A number of different bone graft materials have been developed as alternatives to autograft. These materials may be classified into two major groups, bone graft extenders used to augment autograft, or bone graft substitutes. Several different bone graft materials have been developed including allograft, osteoconductive matrices, demineralised bone matrices, bone marrow aspiration, autologous platelet concentration, growth factors and gene therapy. Allograft is currently the most widely used substitute for autogenous bone. Because any osteogenic cells are eradicated during the tissue processes, allograft is primary osteoinductive with minimal osteoinductive potential. Processing may affects the structural and biological characteristics of a graft. The incorporation of allograft occurs by a process similar to that observed with autograft but more slowly and is less complete. Osteoconductive scaffolds do not contain any osteogenic cells or osteoinductive factors and are used as a composite graft as a carrier for either osteogenic cells or osteoinductive growth factors. They are biocompatible and do not illicit a response. There is also no inherent risk of infection and availability is unlimited. These materials are brittle with poor mechanical properties and need to be protected from excessive biomechanical forces until fully incorporated. A number of osteoconductive scaffolds have been developed including ceramics, calcium sulfate, mineralized collagen, bioactive glasses, and porous metals. Dematerialized bone matrices (DMPs) are osteoinductive with variable osteoconductive properties. DMPs consist of Type I collagen and non-collagenous proteins including multiple signaling proteins. The osteoinductive activity of DMPs is due to a small fraction of bone morphogenic proteins. There is significant variability in the osteoinductive potentials and clinical efficacy of DBMs. DBMs are most effective when combined with autograft or bone marrow aspirate. Bone marrow aspiration provides osteogenetic cells and osteoinductive growth factors but must be combined with an osteoconductive carrier to form a composite graft. It is associated with minimal morbidity compared to the use of autograft and is easily obtained. Unfractionated bone marrow contains only moderate osteogenic potential. Selective retention technology can increase the number of osteogenic cells then combined with an osteoconductive carrier such as a collagen sponge or DBM. Activated platelets release multiple factors that may enhance bone formation by promoting chemotaxis, cellular proliferation and differentiation of stem cells. Platelets do not release BMPs so this autologous platelet concentrate is not inductive. Concentrated platelet rich plasma gel is combined with an osteoconductive scaffold or osteogenic cells to form a composite graft for implantation. The capacity for fusion by this technique may be inferior to autologous graft. Bone morphogenetic proteins are low molecular weight proteins related to the transforming growth factor beta superfamily. They bind receptors on the surface of osteoprogenitor stem cells and activate intracellular signal transduction cascades resulting in the osteoblastic differentiation of pluripotential stem cells. Recombinant BMPs are typically combined with an osteoconductive carrier to form a composite graft. Recombinant BMPs have been used successfully in spinal fusions and may be superior to autograft. Gene therapy involves the transfer of specific DNA sequence into target cells that express the protein of interest. Gene therapy may provide a more potent osteoinductive signal than recombinant growth factors because the sustained local release of osteogentic proteins may be more physiologic than the administration of a single large dose of recombinant factors. There are potential safety concerns and economic issues. Autogenous bone remains the gold standard of graft material; however composite grafts consisting of multiple materials may prove to be efficacious for stimulating a spinal fusion

Aims

Hip arthroscopy (HA) has become the treatment of choice for femoroacetabular impingement (FAI). However, less favourable outcomes following arthroscopic surgery are expected in patients with severe chondral lesions. The aim of this study was to assess the outcomes of HA in patients with FAI and associated chondral lesions, classified according to the Outerbridge system.

Chronic medial collateral ligament (MCL) instability is an unusual clinical problem. Due to the unsatisfactory results of advancement procedures or reconstruction using autologous techniques we have devised a new technique using a non-irradiated tendo achilles allograft construct. Three patients are presented who had symptomatic MCL insufficiency. The laxity was demonstrated clinically (all grade 3) and radiologically using valgus stress views. The tendo achilles was fashioned into a triangular composite graft consisting of a bone plug (30 x 10 mm) and the tendon. The bone plug was attached to the femur at the anatomical insertion of the MCL using an interference screw and the tendon on the tibia using a multiple suture anchor technique. The rehabilitation programme consisted of immediate mobilisation and the use of a brace for twelve weeks. At follow-up (average 12 months) all patients were asymptomatic, had a full range of movements, no increased clinical laxity and no increased radiological laxity to a valgus force at 25 degrees of flexion when compared to the other side. We conclude that this is an effective technique in the treatment of chronic symptomatic MCL laxity

Among the wide variety of bone substitutes presently available, pure β-tricalcium phosphate ceramics have become available (Biosorb®; Aesculap, Tuttlingen). During the first 12 months of a prospective clinical trial, Biosorb® products were implanted in 21 patients. The ceramics were used in a variety of clinical settings, ranging from pelvic osteotomies in children (n=9), to filling of bone cysts or osseous defects (n=4), to dorsal spondylodesis (n=6), as well as for the grafting of pseudarthroses (n=2). Average follow-up period was 13 (6–18) months. The β-TCP granules, when used as part of a composite graft in combination with autologous bone, were completely resorbed after an average period of 14 weeks, while the cubes required 12 to 15 months. The more massive wedges have shown only a decrease in size and radio density. Due to the ability of the cubes and wedges to bear loads of up to 30 MPa, they were successfully implanted during pelvic osteotomies to augment or completely replace the bicortical grafts. Complications or foreign body reactions were not noted. The osseointegration was found to be favorable for all forms. In light of the problems associated with autologous and allogeneic grafts, the use of synthetic bone substitutes will continue to increase. The combination of complete resorption, lack of risk of infection, and load sharing ability make the β-tricalcium phosphate implants a valuable addition to the spectrum of bone replacement products presently available. Their use in pediatric orthopedics could help avoid donor site morbidity including contour changes or growth disturbances, while providing a more stable graft. During the first phase of a prospective clinical trial, we have come to the conclusion, that the β-tricalcium phosphate ceramics represent a real alternative to other bone substitutes

Introduction: Bone is unique with a vast potential for regeneration from cells with stem cell characteristics. With an increasing aging population, clinical imperatives to augment and facilitate tissue repair have highlighted the therapeutic potential of harnessing mes-enchymal populations from bone. We describe laboratory and clinical findings from two clinical cases, where different proximal femoral conditions (AVN, bone cyst) were treated with impacted allograft augmented with marrow-derived allogeneic progenitor cells. Methods: Marrow was aspirated from the posterior superior iliac crest and seeded onto prepared washed morsellised allograft. The seeded graft was left for 40 minutes to allow adherence of the marrow-derived osteoprogenitor cells prior to impaction into the defect. Samples of the impacted graft were taken for in-vitro analysis of cell viability, histology and biochemical analysis of cell number and osteogenic enzyme activity. The total force imparted during impaction was calculated using a load cell, with three independent surgeons performing a laboratory simulation of the impaction technique. Results: Both patients made a rapid clinical recovery after an overnight stay. Imaging confirmed filling of the defects with increased density on plain radiographs suggesting good impaction of the graft composite. Immu-nohistochemical staining of graft samples demonstrated that a living composite graft with osteogenic activity had been introduced into the defects as evidenced by cell tracker green viability and alkaline phosphatase (osteogenic marker) expression and specific activity. The average peak forces during impaction were 0.7kN corresponding to average peak stresses within the graft of 8.3MPa. Similar forces were seen between operators. Discussion: Replacement of bone loss remains a major challenge in orthopaedic practice. Although allograft remains the gold standard where large volumes preclude autograft, allograft has little osteoinductive potential. We demonstrate that marrow-derived cells can adhere to highly washed morsellised allograft, survive the impaction process, and are of the osteoblastic phenotype creating a living composite. Thus we conclude, impacted allograft seeded with autologous marrow cells allows the delivery of a biologically active scaffold for the treatment of bone deficiency. In addition this is a novel straightforward technique, surgeon independent and with applications in a number of orthopaedic scenarios

Prior to the 1970s, almost all bone sarcomas were treated by amputation. The first distal femoral resection and reconstruction was performed in 1973 by Dr Kenneth C Francis at the Memorial Sloan-Kettering Cancer Centre in New York. Since that time, limb-sparing surgery for primary sarcoma has become the mainstay of sarcoma surgery throughout the world. Initially, the use of mega-prostheses of increasing complexity, involving all the major long bones and both pelvic and shoulder girdles, was popularised. In the early 1980s, wide use of massive allograft reconstructions became widespread in both Europe and in multiple centres in the USA and UK. Since that time, increasing complexity in the design of prostheses has allowed for increasing functional reconstructions to occur, but the use of allograft has become less popular due to the development of late graft failures of patients survive past ten years. Fracture rates approaching 50% at 10 years are reported, and thus, other forms of reconstruction are being sought. Techniques of leg lengthening, and bone docking procedures to replace segmental bone loss to tumour are now employed, but the use of biological vascularised reconstructions are becoming more common as patient survivorship increases with children surviving their disease. The use of vascularised fibular graft, composite grafts and re-implantation of extra-corporeally irradiated bone segments are becoming more popular. The improvement in survivorship brought about the use of chemotherapy is producing a population of patients with at least a 65% ten year survivorship, and as many of these patients are children, limb salvage procedures have to survive for many decades. The use of growing prostheses for children have been available for some 25 years, first commencing in Stanmore, UK, with mechanical lengthening prostheses. Non-invasive electro-magnetic induction coil mechanisms are now available to produce leg lengthening, with out the need for open surgery. Whilst many of these techniques have great success, the area of soft tissue attachment to metallic prostheses has not been solved, and reattachment of muscles is of great importance, of course, for return of function. There are great problems in the shoulder joints where sacrifice of rotator cuff muscles is necessary in obtaining adequate disease clearance at the time of primary resection, and a stable shoulder construct, with good movement, has yet to emerge. Similar areas of great difficultly remain the peri-acetabular and sacro-iliac resections in the pelvis. Perhaps the real future of the art of limb salvage will be in the reconstruction of failed major joint replacements where there is great loss of bone stock, and already massive tumour prostheses are providing a salvage pathway for failed standard joint replacement. The final future for limb salvage, however, may not rest with increasing surgical complexity and innovation, but with the development of molecular biology and specific targeted treatments, according to the cytogenetics of a particular tumour. We are on the threshold of yet another quantum change in the approach to cancer management; just as chemotherapy brought a tremendous change in the 1970s, molecular biology is the frontier to make much of the current limb salvage surgery that is performed redundant

Purpose: The management of Dorsal Fracture Dislocations of the PIP joint is challenging, especially for the unstable ones. Complications are common and often lead to functional disability. Many treatment methods have been described in the past, illustrating that no optimal solution has been found. In the Hemi-Hamate autograft technique, introduced by Hastings in 1999, a reconstruction of the volar lip joint surface and stabilization of the joint is achieved. This autograft can be seen as a model of a non vascularised bone-cartilage composite graft. The purpose of the present retrospective study was to evaluate the long term results of the hemi-hamate autograft technique in unstable PIP fracture-dorsal dislocations with special reference to posttraumatic degenerative arthritis common in non vascularized joint transfers. Materials and Methods: We report the results of 9 patients operated between November 2002 and March 2008 and with a minimum follow up of 26 months. The mean follow-up time was 56 months. There were 6 men and 3 women with a mean age at operation of 45 years (23–66). All fractures were unstable with comminution of the volar lip. In 3 patients the dominant hand was involved. The middle finger was injured in 4 patients, the ring finger in 4 and the little finger in 1 patient. All patients were treated with the operation technique described by Hastings and reanalyzed by Williams. The volar base of middle phalanx was debrided and reconstructed by a pre-sized autograft harvested from the dorsal side of the homolateral hamatum, and fixed with mini screws. A standard rehabilitation program was used postoperatively. Clinical (ROM, grip strength), radiographic and subjective outcomes (VAS) were examined in all patients. Results: At the last follow up, the injured finger had an average active ROM at the MCP joints of 97o (90o–115o) at the PIP 69 o (45 o –95 o) and at the DIP 59 o (30 o –90 o). The extension lag in the PIP joints were mean 10 o (0 o –30 o). Grip strength of the injured hand was mean 89% of the uninjured contralateral side. On radiographs, severe arthritis in the treated PIP was found in 2 of 9 patients. Another 2 patients had degenerative arthritis in several PIP. The average subjective score of patient’s satisfaction was 85 (20–100) in a scale 0–100 (100 best). Conclusions: The Hemi-Hamate autograft technique is a technically demanding operation but an alternative to arthrodesis or primary joint arthroplasty in the treatment of Fracture-Dorsal Dislocations of PIP joint. Our results are good and comparable to previously reported results (Williams 2001). Some deterioration will occur regarding joint osteoarthritis but a high degree of subjective patient satisfaction was found. Further studies and methods to decrease the osteoarthritis would be preferential